In a semiconductor switching device like a Field Effect Transistor (FET) or a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Insulated gate bipolar transistor (IGBT), Bipolar junction transistor (BJT) commonly used to get a chopped wave from constant DC source. In the process of chopping, the switching devices are vulnerable to both electromagnetic (EM) noise and thermal run away problems depending upon the method of switching. The gate terminal voltage and current control is common method of switching any semiconductor devices. In general, high rate of change of gate triggering currents are recommended for fast turning ON and turning OFF the switching devices. The high rate of change of currents (both gating and main circuit) interact with inductive and capacitive circuits associated with the semiconductor switching device and cause electromagnetic noise in the circuit. As per the international standards, the EM noise (conductive and radiated) should be within a predefined limit. In order to bring noise levels down, the switching devices must operate with high turn ON and Turn OFF times.
However, operating the semiconductor-switching device at high turn ON and turn OFF times leads to more switching loss. thermal behaviour. The more switching losses intern led to switch thermal runaway issues.
Hence it is evident that there is a trade-off between the EM noise and thermal run away issues. Conventional systems address either of regulation of EM noise or reducing thermal problems in the semiconductor switching device.
FIG. 1A shows a conventional circuit for controlling amplitude of gate current of a semiconductor switching device. Here, CGS refers to capacitance of gate terminal and source terminal of the semiconductor switching device. A voltage across the capacitor CGS decides ON time and OFF time of the semiconductor switching device. Very fast charging of Cgs causes EM noise issues thermal behaviour slow switching leads to long interval of ON time and OFF time leading to switch thermal run away problems.
FIG. 1B shows a conventional circuit for contrsolling gate current of a semiconductor switching device. Here, an inductor is placed at input gate terminal of the semiconductor switching device. The inductor can be used to regulate gate current, thereby try to operate the semiconductor switching device high turn ON and turn OFF intervals thereby reduce the electromagnetic noise problems but provoke thermal issues. However, value of inductance varies with different circuits. The value of inductance has to be calculated for individual circuit. Therefore, the circuit of FIG. 1B does not provide a common solution that can be utilized for different circuits associated with the semiconductor switching device.
The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.